Which image for which purpose?

[Granjow]

Hi there,

I have a beginner’s question regarding the different images that can be created with the mender-image-* features: Which are used for which purpose?

My current understanding:

• hddimg can be flashed on a USB stick for later installation on the system (boot and install partition)
• uefiimg is supposed to be burned directly on the target media (alread contains 4 partitions)
• mender is the artifact for mender deployment
• ubi for, well, usage as UBI image
• sdimg same as uefiimg

Is this correct?

Thanks,
Simon

[kacf]

@Granjow

• hddimg can be flashed on a USB stick for later installation on the system (boot and install partition)

This is not used in Mender setups. It probably comes from one of the entries in IMAGE_FSTYPES, and is built by poky, not meta-mender.

@Granjow

• uefiimg is supposed to be burned directly on the target media (alread contains 4 partitions)
• mender is the artifact for mender deployment
• ubi for, well, usage as UBI image

Correct.

@Granjow

• sdimg same as uefiimg

Pretty much, except they are rarely used at the same time. uefiimg is typically used on x86, and on ARM if you are using the default mender-grub integration. sdimg is used on ARM platforms which have done custom U-Boot integrations and have turned off mender-grub and mender-image-uefi. In most cases only one of the two images will be built, so you can check your build directory for which one to use.

[Granjow]

Thanks @kacf for the answer.
I submitted a MR to extend the docs on that topic.